Push-button control



R. DEMEULENAERE EI'AL 2,544,918

PUSH-BUTTON CONTROL March 13, 1951 Filed May 14, 1945 j a) I, 1 3' O \9 N V INVENTORS I 1? .fieme w Lena/e1 6 H.1)emeuLen 0, 61%

- ATTORNEYS Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE 2,544,918 PUSH-BUTTON CONTROL Robert Demeulenaere and Marcel Demeulenaere, New York, N. Y.

Application May 14, 1945, Serial No. 593,586

, 16 Claims. 1

This invention relates to improvements in push button control devices of the type employed for automatically tuning radio receiving sets, and has for its object not only to enable swift and convenient adjustment such as required in changing the selection of broadcast stations but also to afford accuracy of adjustment within such narrow limits as to assure the setting of the tuning device at each operation of the push buttons with a high degr'eeof precision.

A further object is to simplify the structure and organization of the parts whereby the cost of production of push button control mechanisms is reduced and the dimensions thereof reduced suiiiciently to permit compact accommodation in spaces of small size.

In the accompanying drawings wherein an approved employment of the invention is illustrated:

Figure 1 is a transverse sectional view through the push button control device.

Figure 2 is a longitudinal sectional view therethrough.

Figure 3 is a fragmentary and rear elevation of the device.

Figure 4 is a detail section on the line 44 of Figure 3.

Figure 5 is an enlarged detail view illustrating the cooperation between the teeth of the drive gear and the thread of the actuating shaft. V

Figure '6 is a sectional view on the line 6t of Figure 5.

Figure '7 is a sectional View on the line l''! of Figure 2.

Referring to the drawing in detail, the numeral iii indicates a hollow casing the front wall of which slidably supports a plurality of actuating shafts H formed at the exposed end thereof to constitute push buttons conveniently operable for changing from station to station to selectively tune the radio which the invention is applied. The rear extremity of each shaft is slidable in a slot l2 formed in the rear wall of the casing and the shafts are normally pressed downwardly at the rear ends by bearing member l3 engaged over the shafts and subjected to the tension of springs M. The shafts are normally held in forwardly projected position by springs l5a and the forward movement thereof is limited by a stop flange Ha. A pawl 15 pivotally mounted at It is engageable in a detent ll formed in the shaft l I. The pawl I5 is common to the several shafts l I and extends transversely of them and is normally retained in operative position by a spring Ha. When one of the shafts is moved rearward- 1y into operative position, the pawl i5 is deflected thereby releasing the shaft previously actuated and engaging beyond a second detent I -8 formed in close proximity to the forward extremity of the shaft.

The medial portion of each shaft H is formed with a screw 19 having a prominent and Welldefined thread engaging the teeth of an adjustable drive gear 29 supported on a tuning shaft 2i which latter is 'rotatably supported in the opposite end wall of the casing Ill.

Each adjustable drive gear 2 0 is accurately r'etained in predetermined position longitudinally of the shaft M by engagement against an abutment pin 22, such engagement being maintained by springs 23 confined between collars 24 on the shaft 2| and the drive gears Each drive gear 2-0 is rotatably mounted on the shaft -2i and is provided with a drive pin 2 5 engagea-bl-e with the related abutment pin 22 for imparting rotary movement in one direction to the tuning shaft 2|.

The shaft 2! is movable between limiting stops Zia through an angle of degrees and is subjected to the influence of a spring 2lb tending to turn the shaft in the direction of the a'rrow 26 in Figure l.

A series of adjusting shafts 27 corresponding in number to the actuating shafts H are slidably and rotatably mounted in the front and rear Walls of the casing in and projected a distance for= Wardly cf the latter for convenience in manipulating them. The rear portion of each adjusting shaft is provided with axially elongated teeth 28 meshing with a gear wheel '29 rigidly mounted on the related actuating shaft 1 l whereby rotary adjusting movement of the shaft 2"! is transmitted to the related shaft H. The axial extension of the rear teeth 28 permits freedom of axial movement of the actuating shaft ll throughout its range of longitudinal movement without, however, altering the angular position of the shaft H. Each adjusting shaft 2'! is normally held in forwardly extended position by a spring 30 and the rear extremity thereof is provided with a toothed disk 3|, one of the teeth of which is engageable in one of a circular series'of recesses 32 formed in the rear wall of the casing ill. In practice it is permissible to provide 17 teeth on each disk 3! and thirty-two recesses 32 for a purpose which hereinafter appear. The disk 3! is normally fiat and when the adjusting shaft 2'! is moved rearwardly to change the ad-'* justment of the related actuating shaft It, the tooth of the disk I I engagedin one of the recesses 32 is disengaged therefrom and the shaft 21 may be freely rotated. When the shaft 21 is released, however, it is pressed forwardly by the spring 30 and the tooth of the disk 3| nearest the adjacent one of the recesses 32 engages therein while the remaining teeth are flexed angularly, as shown in Figure. 1. The engagement of one of the teeth of the disk 3| in the recess 32 serves to lock the adjusting shaft 21 in the selected angular position and by engagement of the rear wheel 29 with the teeth 28, the related shaft H is also prevented from turning about its axis. It is also desirable that the ratio between the gear wheels 28 and 29 should be 1 to 4 for improving the precision of adjustment of the device as will hereinafter more fully appear.

As stated above, the tuning shaft 2| turns through an angle of 180 degrees throughout the range of tuning adjustment thereof. Assuming that the shaft in the position shown in Figure 1 has been turned in the direction of the arrow 26 into engagement with the stop 2 la limiting rotary movement in that direction and that the drive pin 25 is in engagement with the abutment pin 22, when the actuating shaft H is pressed rearwardly, the drive gear 22 is turned through a corresponding angle. -When the actuating shaft H is fully actuated, the pawl enters the detent l8 and locks the shaft in operative position, the gear wheel 29 engaging and sliding along the gear teeth 28 and thereby preventing rotary movement of the actuating shaft. Upon actuation of one of the other actuating shafts to tune the radio for the reception of a different broadcast station, the inclined surface of the newly actuated shaft l l deflects the pawl 15 thereby releasing the previously operated shaft H which is restored to initial position by the spring to Q5, whereas the shaft H last actuated is retained in operative position by engagement of the pawl 15 with the detent l8.

In case it may be desired to adjust the drive gear for setting the tuning shaft 2! in some other position within its range of angular movement for automatically tuning in a different station upon operation of the actuating shaft II, the adjusting shaft 21 is pressed rearwardly against the tension of the spring 39 thereby disengaging the teeth of the disk 3! from the recess 32 and thereby permitting freedom of rotary movement of the adjusting shaft. The shaft H is pressed rearwardly to its operative position in which it is locked by engagement of the pawl IS with the detent l8. The shaft 21 is then rotated to engage the drive pin 25 with the abutment pin 22 and in this manner the tuning shaft 21 is turned into the angular position most favorable for the best reception of the selected broadcast station. This adjustment of the drive gear angularly with respect to the tuning shaft is effected by the camming action of the screw thread 19 upon the teeth of the drive gear 20. After the desired adjustment has been effected, the shaft 21 is released and moved forwardly by the spring 30. Thus one of the teeth of the disk 3! is engaged in one of the recesses 32 and the shaft 2'! locked in the selected angular position. Simultaneously the actuating shaft H and related parts are also locked and the adjustment thus maintained so that at each actuation of the shaft H the tuning shaft 2G is turned to the same angular position.

Such lost movement between the parts as might impair the accuracy of adjustment is compensated by the spring normally tending to turn the shaft 21 and maintaining point of contact between the teeth of the drive gear 20 and the screw thread H! as shown in detail in Figures 5 and 6. A close fit of the teeth of the gear 29 with the teeth 28 obviating lost motion between these parts is maintained by the spring 14 coacting with each actuating shaft H, the tension of the spring tending to press the gear 29 into the teeth 28.

It is of the utmost importance for the extreme accuracy of adjustment in tuning the radio receiving set to lock each actuating shaft H and the related drive gear It in position within the limitations of the smallest practical angle. This is accomplished, first, by the l to 4 ratio between the gears 28 and 29, and, second, by the provision of 1'7 teeth on the disk 3| and thirty-two recesses 32 in the casing l0. Thus the greatest angular difference between the teeth 3| and a recess 32 is The ratio between the gears 28 and 29 being 1 to 4, the angular difference between the adjusting shaft 2? and the actuating shaft H is The screw thread [9 has a pitch of 16 per inch and the drive gear 28 sixteen teeth in the portion thereof corresponding with the degrees through which the tuning shaft 2| is movable. Consequently the angular difference on the tuning shaft in effecting adjustment thereof is reduced to 180 16X4X17X32 What we claim is:

l. A device for turning a shaft through variable predetermined angles comprising an abutment on said shaft, a rotatable toothed drive member movable relative to said shaft, means associated with said drive member and engageable with said abutment for turning said shaft, a rotatable and axially reciprooable actuating member, and teeth on said actuating member meshing with said toothed drive member, the teeth on said actuating member being inclined whereby during rotary movement of the actuating member the drive member is carnmed to vary the degree of rotation of the drive member with relation to the abutment.

2. A device for turning a shaft through variable predetermined angles comprising an abutment on said shaft, a rotatable toothed member movable relative to said shaft, means associated with said drive member andengageable with said abutment to impart rotary movement to said shaft, a rotatable and longitudinally movable actuating member having a screw thread meshing with the teeth of said toothed member whereby upon longitudinal movement of the actuating member the toothed member is turned through a relatively wide fixed angle to impart rotary movement to said shaft whereas when said actuating member is rotated, the toothed member is cammed by the screw thread and turned through a relatively small angle for adjusting the movement of the toothed member with respect to said abutment;

3. A device for turning a shaft through variable predetermined angles comprising a rotatable and reciprocable actuating member having a equals 20" 5 screw thread, a rotatable drive member movable relative to said shaft, said drive member having teeth meshing with the screw thread and being settable thereby in selected angular positions with respect to said shaft by rotation of said actuating member, said drive member, when set, being rotatable through a fixed angle by said thread during reciprocation of said actuating member, and an abutment on said shaft engageable by means associated with said drive member for imparting rotary movement to said shaft in one direction.

4. A device as claimed in claim 3 provided with means to releasably lock the actuating member at the limit of its reciprocating movement during which said setting movement is imparted to said shaft.

5. A device as claimed in claim 3 provided with means to releasably lock the actuating member at the limit of its reciprocating movement during which said setting movement is imparted to said shaft, and means for retaining the actuating member in adjusted angular position.

6. A device as claimed in claim 3 provided with means for angularly adjusting said actuating member.

7. A device as claimed inclaim 3 provided with means for angularly adjusting said actuating member, and means for locking said actuating member in adjusted angular position.

8. A device as claimed in claim 3 provided with a. member for locking said actuating member in adjusted angular position, a, plurality of teeth on said locking member, and a plurality of recesses arranged to receive the locking teeth singly in 35 various angular adjustments of said actuating member.

9. A device as claimed in claim 3 provided with a member for locking said actuating member in adjusted angular position, a plurality of teeth on said locking member, a plurality of recesses arranged to receive th 10cking teeth singly in various angular adjustments of said actuating mem- I gular positions, and a manually operable reduction gear connecting said locking means with said a ltilating member operable when said locking n iians is released to angularly adjust said actuatmg member.

A device as claimed in claim 3 provided with releasable locking means settable in various angular positions, a manually operable reduction gear connecting said locking means with said actuating member operable when said locking means is released to angularly adjust said actuatiri'g' member, and means to compensate for 10st motion in said reduction gear.

11-2. A device as claimed in claim 3 provided with means tending to rotate said shaft in the opposite direction and preventing backlash of said shaft.

A device as claimed in claim 3 wherein said 5 ew thread constitutes the teeth of a rack 01 erable during reciprocation w of the actuating member to coact with the teeth of and rotate'said drive member.

.14. A device as claimed in claim 3 provided with means yieldably retaining said drive member in a fixed position axially of said shaft.

A device as claimed in claim 3 provided with means yieldably retaining said drive member in engagement with said abutment to determine the position of said drive member axially of said shaft.

f 16. A device as claimed in claim 3 wherein said actuating member is constituted by a manually operable push button.

ROBERT DEMEULENAERE. MARCEL DEMEULENAERE.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number 

